In recent days, various diseases attributable to a virus have come to be a serious social problem. It is known, for example, that diseases such as AIDS, viral hepatitis type B, viral hepatitis type C and adult T-cell leukemia are caused by HIV, HBV, HCV and HTLV-I, respectively. Furthermore, appearance of new viral diseases such as Ebola hemorrhagic fever and Marburg disease caused by Filovirus and hemorrhagic fever with renal syndrome caused by Hantaan virus has posed a great threat to humans.
As one of the important countermeasures for the prevention of the diseases attributable to a virus, infection prevention can be given. In various fields ranging from the production sites of blood derivatives or vaccines, hospitals and bio-related research institutes to our daily life, countermeasures against infection with a virus are being requested. As a technique for the removal or inactivation of a virus, a heat treatment method is well known, but it is difficult to carry out heat treatment in some cases, for example, where a biological component which is degenerated or deactivated by the heat treatment is contained or where the object to be treated is an organism itself.
Known examples of the non heat-treating method include:
(1) a method of inactivating a virus by using a virus inactivating agent; PA1 (2) a method of making a virus adsorb to a material having a target cell of the virus or a receptor immobilized thereto, thereby removing the virus (U.S. Pat. No. 4869826); and PA1 (3) a method of capturing a virus in water by using polyvinyl pyridinium beads which have been insolubilized by crosslinking (Japanese Patent Publication No. SHO 62-41641). PA1 (1) a method of forming anti-viral fine particles by forming fine particles of a hydrophobic high-molecular chain to be a base material and then binding or grafting a hydrophilic high-molecular chain on the surface of the resulting base material; PA1 (2) a method of forming anti-viral fine particles by preparing hydrophobic fine particles using a monomer or macromonomer having a functional group convertible, by hydrolysis or the like, from a hydrophobic group to a hydrophilic group; and then converting the hydrophobic fine particles into a hydrophilic high-molecular chain by making use of hydrolysis or the like; and PA1 (3) a method of forming anti-viral fine particles by using hydrophilic and hydrophobic raw materials in combination, for example, using a hydrophilic macromonomer and a hydrophobic monomer or a hydrophobic macromonomer and a hydrophilic monomer in combination.
The above-described method (1) however involves problems in the safety of a chemical used for the inactivation of a virus, separation of the chemical from the treatment solution contained in the inactivated virus and degeneration of useful proteins in the treatment solution. As a method of inactivating a virus by using a chemical, an inactivation method with a surfactant, aldehyde or .beta.-propiolactone has already been reported. It is however known that the inactivating method of a virus by using such a chemical degenerates or impairs physiological activity of a protein component. According to the report, .beta.-propiolactone remains in the treatment solution even after inactivation of a virus and exhibits carcinogenicity, so that it has not yet come into wide use. Also proposed is a method of removing a virus by treating the virus with a liposoluble virus inactivating agent and then distributing said virus inactivating agent in a natural oil or synthetic triglyceride of less toxicity (Japanese Patent Application Laid-Open No. SHO 62-240623). This method is however accompanied with the drawback that it requires cumbersome and long-time operation.
The above-described method (2) is not satisfactory from the viewpoints of adjustment of a material, stability (maintenance of activity) and economy because a cell itself or its receptor is employed as the material. In addition, it is accompanied with the drawback that owing to high specificity to a target virus, it cannot be applied to many nonspecific viruses.
By the above-described method (3) which uses a polyvinyl pyridinium structure, a virus can be captured and removed from tap water or the like having a small protein content. From the plasma or a cellular culture solution which contains proteins and lipids at high concentrations, on the other hand, a virus cannot be removed effectively because nonspecific adsorption of protein components and lipids mainly occurs.
Accordingly, an object of the present invention is to provide an antiviral raw material which has overcome the above-described problems. More specifically, an object of the present invention is to provide a virus-infection preventive which is, for the purpose of preventing the infection of a virus, applied in advance to the mucous tissue, thereby inhibiting the invasion of a virus; or a virucide which can safely and conveniently remove or inactivate a virus existing in a solution or the air.